EMPLOYEES WORKING for the city of Boston, Google, Sanofi, and retailers at Assembly Row in Somerville will be able to ride the MBTA subways and buses for free under a two-year pilot program paid for by the employers.

The new initiative, announced on Monday, is an extension of an existing program run by MIT that allows the university to pay after-the-fact for individual trips taken by employees and students. The MIT program, which has been in place since 2016, also offers significant discounts on monthly passes and commuter rail service.

Between the four employers, a total of nearly 10,000 employees will be covered under the new program, with the city of Boston accounting for roughly 4,000.

In a joint press release, Boston officials said the program will begin next year and provide city workers with a major new benefit while giving the municipality a better understanding of how employees get to work that could influence transit-related decisions in the future.

Boston Mayor Michelle Wu is a leading advocate of making bus and subway service free. The city is currently paying the cost of making three MBTA bus routes free.

Beth O’Neill Maloney, executive director of the Kendall Square Association, said two of the organization’s members – Google and Sanofi – will now be able to follow in the footsteps of a third member, MIT. “Our members are innovating around their commuter culture, parking assets, and carbon footprint as a part of their commitment to sustainability,” she said in a statement.

Fred Salvucci, the former state transportation secretary who teaches at MIT and lobbied for the original MIT program, called the announcement “tremendously significant.”

Salvucci said the MBTA program is a great benefit for MIT employees and students and also for the university itself, which has been able to avoid the costly construction of new parking spaces on its campus. MIT identification cards come with a chip that allows the MBTA to track usage and bill the university, Salucci said.

By making it a pay-as-you-go program, Salvucci said, employers only pay for the trips their employees actually take.  Salvucci pointed out that employees also get their non-work-related trips paid for as well. He said the original idea for the program was put forward by an MIT student.

David Webster of Federal Realty Investment Trust, who heads Assembly Connect, said the program makes sense for retailers struggling to fill job openings. “By subsidizing transit passes for retail employees, we’re helping retailers attract and retain essential workers for whom the costs of parking and transportation are often prohibitive,” he said.